创建一个名为“学号+姓名”的用户信息管理程序，该程序用于输入、保存、列表展示和选择删除。

“用户信息管理”程序录入界面对应布局文件的图形化视图，如下图所示。

目   录

1、工程结构图

1.1、activity_main.xml

1.2、MainActivity.java

1.3、MyHelper.java

2、运行效果图

1、工程结构图

1.1、activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="用户姓名" />

    <EditText
        android:id="@+id/name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入姓名！" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="用户密码" />

    <EditText
        android:id="@+id/pwd"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入密码！" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="用户性别" />

    <RadioGroup
        android:id="@+id/rdg"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <RadioButton
            android:id="@+id/male"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="男" />

        <RadioButton
            android:id="@+id/female"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="女" />

    </RadioGroup>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="兴趣领域" />

    <CheckBox
        android:id="@+id/cb1_affairs"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:checked="true"
        android:text="时事" />

    <CheckBox
        android:id="@+id/cb2_science"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:checked="true"
        android:text="科技" />

    <CheckBox
        android:id="@+id/cb3_entertainment"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="文娱" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/add"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="添加信息" />

        <Button
            android:id="@+id/delete"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="删除信息" />

        <Button
            android:id="@+id/update"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="更改信息" />

        <Button
            android:id="@+id/query"
            android:layout_weight="1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="查询信息" />

    </LinearLayout>

    <TextView
        android:id="@+id/show"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

1.2、MainActivity.java

package cn.lwx.my;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.RadioGroup;
import android.widget.Switch;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private EditText et_name;
    private EditText et_pwd;
    private RadioGroup radioGroup;
    private CheckBox cb1_affairs;
    private CheckBox cb2_science;
    private CheckBox cb3_entertainment;
    private String Gender = "男";
    private String[] checkBox = {"时事", "科技", ""};//多选框字符数组
    private Button btnAdd;
    private Button btnDelete;
    private Button btnUpdate;
    private Button btnQuery;
    private TextView mTvShow;
    MyHelper myHelper;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        myHelper = new MyHelper(this);
        initView();//初始化控件
    }

    private void initView() {
        et_name = (EditText) findViewById(R.id.name);
        et_pwd = (EditText) findViewById(R.id.pwd);
        radioGroup = (RadioGroup) findViewById(R.id.rdg);
        // 判断用户选择的性别
        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                if (checkedId == R.id.male) {
                    Toast.makeText(MainActivity.this, "男", Toast.LENGTH_SHORT).show();
                    Gender = "男";
                } else {
                    Toast.makeText(MainActivity.this, "女", Toast.LENGTH_SHORT).show();
                    Gender = "女";
                }
            }
        });
        cb1_affairs = (CheckBox) findViewById(R.id.cb1_affairs);
        cb2_science = (CheckBox) findViewById(R.id.cb2_science);
        cb3_entertainment = (CheckBox) findViewById(R.id.cb3_entertainment);
        btnAdd = (Button) findViewById(R.id.add);
        btnDelete = (Button) findViewById(R.id.delete);
        btnUpdate = (Button) findViewById(R.id.update);
        btnQuery = (Button) findViewById(R.id.query);

        mTvShow = (TextView) findViewById(R.id.show);

        //多选框监听器
        OnBoxClickListener listener = new OnBoxClickListener();
        cb1_affairs.setOnClickListener(listener);
        cb2_science.setOnClickListener(listener);
        cb3_entertainment.setOnClickListener(listener);

        //增删改查
        btnAdd.setOnClickListener(this);
        btnDelete.setOnClickListener(this);
        btnUpdate.setOnClickListener(this);
        btnQuery.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        String name;
        String pwd;
        String interest = checkBox[0] + "、" + checkBox[1] + "、" + checkBox[2];
        SQLiteDatabase db;
        ContentValues values;

        switch (v.getId()) {
            case R.id.add:
                name = et_name.getText().toString();
                pwd = et_pwd.getText().toString();
                db = myHelper.getWritableDatabase();
                values = new ContentValues();
                values.put("name", name);
                values.put("pwd", pwd);
                values.put("gender", Gender);
                values.put("interest", interest);
                db.insert("person", null, values);
                Toast.makeText(this, "信息已添加！", Toast.LENGTH_SHORT).show();
                db.close();
                break;
            case R.id.delete:
                db = myHelper.getWritableDatabase();
                db.delete("person", null, null);
                Toast.makeText(this, "信息已删除！", Toast.LENGTH_SHORT).show();
                mTvShow.setText("");
                db.close();
                break;
            case R.id.update:
                db = myHelper.getWritableDatabase();
                values = new ContentValues();       // 要修改的数据
                values.put("pwd", pwd = et_pwd.getText().toString());
                values.put("gender", Gender);
                values.put("interest", interest);
                db.update("person", values, "name=?",
                        new String[]{et_pwd.getText().toString()}); // 更新并得到行数
                Toast.makeText(this, "信息已修改", Toast.LENGTH_SHORT).show();
                db.close();
                break;
            case R.id.query:
                db = myHelper.getReadableDatabase();
                Cursor cursor = db.query("person", null, null,
                        null, null, null, null);
                if (cursor.getCount() == 0) {
                    Toast.makeText(this, "没有数据！", Toast.LENGTH_SHORT).show();
                } else {
                    cursor.moveToFirst();
                    mTvShow.setText("Name: " + cursor.getString(1) + " ; Pwd: " + cursor.getString(2) +
                            " ; Gender: " + cursor.getString(3) + " ; Interest: " + cursor.getString(4));
                }
                while (cursor.moveToNext()) {
                    mTvShow.append("\n" + "Name: " + cursor.getString(1) + " ; Pwd: " + cursor.getString(2) +
                            " ; Gender: " + cursor.getString(3) + " ; Interest: " + cursor.getString(4));
                }
                cursor.close();
                db.close();
                break;
        }
    }

    class OnBoxClickListener implements View.OnClickListener {
        @Override
        public void onClick(View v) {
            CheckBox box = (CheckBox) v;
            if (box.isChecked()) {
                if (box.getId() == R.id.cb1_affairs) {
                    Toast.makeText(MainActivity.this, "1-时事-被选中！", Toast.LENGTH_SHORT).show();
                    checkBox[0] = "时事";
                } else if (box.getId() == R.id.cb2_science) {
                    Toast.makeText(MainActivity.this, "2-科技-被选中！", Toast.LENGTH_SHORT).show();
                    checkBox[1] = "科技";
                } else if (box.getId() == R.id.cb3_entertainment) {
                    Toast.makeText(MainActivity.this, "3-文娱-被选中！", Toast.LENGTH_SHORT).show();
                    checkBox[2] = "文娱";
                }
            } else {
                if (box.getId() == R.id.cb1_affairs) {
                    Toast.makeText(MainActivity.this, "1-时事-未被选中！", Toast.LENGTH_SHORT).show();
                    checkBox[0] = "";
                } else if (box.getId() == R.id.cb2_science) {
                    Toast.makeText(MainActivity.this, "2-科技-未被选中！", Toast.LENGTH_SHORT).show();
                    checkBox[1] = "";
                } else { // if (box.getId() == R.id.cb3_entertainment)
                    Toast.makeText(MainActivity.this, "3-文娱-未被选中！", Toast.LENGTH_SHORT).show();
                    checkBox[2] = "";
                }
            }
        }
    }
}

1.3、MyHelper.java

package cn.lwx.my;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

public class MyHelper extends SQLiteOpenHelper {

    public MyHelper(Context context) {
        super(context, "lwx.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create Table person(id INTEGER PRIMARY KEY AUTOINCREMENT, " +
                "name VARCHAR(20), pwd VARCHAR(20), gender VARCHAR(6), interest VARCHAR(20))");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

2、运行效果图

写于，2020年6月16日，晚。

咦，好巧。我人生中第一部手机，是在2018年6月16日买的。【高考后，不久~~~】

目前，还有一些小Bug！！！